feat: add inspection_expiry/has_etc/tire_type fields, icons in schedule view, and WebSocket real-time sync

Co-authored-by: pdf114514 <57948770+pdf114514@users.noreply.github.com>
Agent-Logs-Url: https://github.com/pdf114514/CarReservation/sessions/6d0f25ae-6db4-4937-ae2b-6674456a5ca1

frontend/src/hooks/useWebSocket.js

@@ -0,0 +1,83 @@
+import { useEffect, useRef, useState, useCallback } from 'react';
+
+const WS_BASE = (() => {
+  if (import.meta.env.VITE_WS_URL) return import.meta.env.VITE_WS_URL;
+  const loc = window.location;
+  const proto = loc.protocol === 'https:' ? 'wss:' : 'ws:';
+  // Use the same origin as the page; in development the Vite dev server
+  // proxies /ws to the backend, and in production nginx does the same.
+  return `${proto}//${loc.host}/ws`;
+})();
+
+const RECONNECT_DELAYS = [1000, 2000, 4000, 8000, 15000, 30000]; // ms
+
+/**
+ * Maintains a WebSocket connection with automatic reconnection.
+ *
+ * @param {(message: object) => void} onMessage - Called for each parsed JSON message.
+ * @returns {{ status: 'connecting'|'connected'|'disconnected'|'error' }}
+ */
+export default function useWebSocket(onMessage) {
+  const [status, setStatus] = useState('connecting');
+  const wsRef = useRef(null);
+  const retryCountRef = useRef(0);
+  const unmountedRef = useRef(false);
+  const retryTimerRef = useRef(null);
+  const onMessageRef = useRef(onMessage);
+
+  // Keep onMessage ref up-to-date without re-running the effect
+  useEffect(() => {
+    onMessageRef.current = onMessage;
+  }, [onMessage]);
+
+  const connect = useCallback(() => {
+    if (unmountedRef.current) return;
+
+    setStatus('connecting');
+    const ws = new WebSocket(WS_BASE);
+    wsRef.current = ws;
+
+    ws.onopen = () => {
+      if (unmountedRef.current) { ws.close(); return; }
+      retryCountRef.current = 0;
+      setStatus('connected');
+    };
+
+    ws.onmessage = (event) => {
+      try {
+        const msg = JSON.parse(event.data);
+        onMessageRef.current(msg);
+      } catch {
+        // ignore malformed messages
+      }
+    };
+
+    ws.onclose = () => {
+      if (unmountedRef.current) return;
+      const delay = RECONNECT_DELAYS[Math.min(retryCountRef.current, RECONNECT_DELAYS.length - 1)];
+      retryCountRef.current += 1;
+      // After exhausting all backoff levels, keep status as 'error'
+      if (retryCountRef.current > RECONNECT_DELAYS.length) {
+        setStatus('error');
+      } else {
+        setStatus('disconnected');
+      }
+      retryTimerRef.current = setTimeout(connect, delay);
+    };
+
+    ws.onerror = () => {
+      // onclose will fire right after, which handles reconnect
+    };
+  }, []);
+
+  useEffect(() => {
+    connect();
+    return () => {
+      unmountedRef.current = true;
+      clearTimeout(retryTimerRef.current);
+      wsRef.current?.close();
+    };
+  }, [connect]);
+
+  return { status };
+}